Polymeric biomaterials must be cleaned and sterilized prior to use in any invasive medical procedure. This must be done without damaging to the surface or bulk properties, and without compromising biocompatibility. A low temperature sterilization process based on liquid or supercritical carbon dioxide (CO2) technology has been proposed. Carbon dioxide (CO2)-based fluids have been tested for both inactivation and sterilization of organisms and compatibility with biomaterials. Compressed CO2 kills many clinically relevant gram positive vegetative bacteria (e.g. Staphylococcus aureus) and gram negative vegetative bacteria (e.g. Escherichia coli). Also, polymers have been processed with compressed CO2 without degrading chemical and mechanical properties. If this technology can be developed, then the entire field of implantable biopolymers, especially those being developed for cell-based tissue engineering, it could overcome a major barrier to commercialization. The purpose of the present work is to evaluate the CO2 sterilization process in terms of both sterilization effectiveness and its influence on the physical properties of a model hydrogel. The effects of CO2 treatment on water uptake, drying curves, thermal behavior and morphology of poly (acrylic acid-co-acrylamide) potassium salt gel will be reported. The ability of CO2-based fluids to kill Staphylococcus aureus and Escherichia coli entrapped on a polymeric matrix will also be reported.